This invention relates to an automatic closure assembly for an outhouse, compost toilet or pit commode for isolating and sealing a compost pit when not in use for minimizing the escape of odors from the pit into and about the outhouse and surroundings.
Broadly speaking, such closure assemblies have long been known and used in the prior art. See, for example, U.S. Pat. No. 126,745 issued to N. P. Rider on May 14, 1872; U.S. Pat. No. 734,336 issued to W. S. Johnson on Jul. 21, 1903; U.S. Pat. No. 898,225 issued to C. Kelley on Sep. 8, 1908; U.S. Pat. No. 1,210,186 issued to M. M. Marcuse on Dec. 26, 1916; U.S. Pat. No. 1,296,666 issued to G. E. Kinch on Mar. 11, 1919; U.S. Pat. No. 1,442,142 issued to L. L. Fusan on Jan. 16, 1923; U.S. Pat. No. 2,946,065 issued to D. L. Smith on Jul. 26, 1960; U.S. Pat. No. 3,366,976 issued to C. W. Swanson on Feb. 6, 1968; U.S. Pat. No. 3,430,269 issued to T. T. Bradshaw on Mar. 4, 1969; and U.S. Pat. No. 4,054,958 issued to E. G. Widham on Oct. 25, 1977. See also Australian Pat. No. 7782/27 published Mar. 27, 1928; Australian Pat. No. 17,125/28 published Oct. 8, 1929; and Australian Pat. No. 232856 published Aug. 25, 1960.
All of the previously mentioned prior art assemblies include closure means or doors which automatically open and close when the toilet seat is lowered and raised, respectively. But each of these assemblies uses either some type of spring or counterweight or both to actuate the closure. By counterweight, I mean a mass placed to provide a bending moment on an opposite side of a fulcrum or pivot point from the weight of a door or closure tiltable about such fulcrum or pivot point. Thus, the counterweight provides a bending moment acting in a rotational direction which is greater than the bending moment of the door or closure itself and which acts in a direction opposite to the latter bending moment. A spring, of course, is susceptible to aging, rusting, becoming permanently stretched, wearing out or otherwise failing as the result of repeated usage.
By means of the present invention I provide an automatic, normally closed closure assembly for an outhouse toilet which does not employ either springs or counterweights for actuation of the doors but, which nevertheless still utilizes gravity to bias the doors toward a normally closed position.